Process of extracting oleo-resin from the peel of citrus fruits.



UNITED STATES Patented November 22, 3.96%.

I r Pannier tissue,

EDWARD J. SHEEHAN, OF PASADENA, CALlFORNIA, ASSlG-NOR TO SAN GABRIEL VALLEY ESSENTIAL OIL C(JMPANY, OF PASADENA, CALE- FORNIA, A CORl ORATION OF CALIFQRNIA.

PROCESS OF EXTRAQTING OLEO-RESIN FROM THE,PEEL 0F QITRUS FRUITS.

SPECIFICATION forming part of Letters Patent No. 77'5,502, dated November 22, 1904. Application filed June 18, 1903. Serial No. 162,100. (No specimens.)

-To all whom it may concern:

\ Be it known that I, EDWARD J. Snnnmm, a citizen of the United States, residing at Pasadens, Los Angcles county, State of California, have invented certain new and useful Improvements in Processes of Extracting Oleo-Resin from the Peel of Citrus Fruits, of which the followingis afull, clear, and exact description.

My invention relates to the production of oleo-resin from the citrus class of fruits; and it consists of a new and improved process or method of extracting the oleo-resin from such fruits and in the purified product obtained therefrom.

Heretofore a class of essential oils has been obtained from the fresh peel of oranges and lemons by pressure which bursts the oil-cells, the oil being collected by various means. The best of these processes, so far as they are known, produce products classified as essential oils, but which are lacking, except perhaps to a minor but inappreciablc extent, in the acid and neutral resins, particularly the latter, these acids possessing a flavoring power char acteristic of the fresh fruit and supplementing the flavoring power of the citral in the pool of such fruits.

I have found as the result of repeated and long-continued use of my new process hereinafter described and by analyses of the product so obtained that the peel of orange and lemon in the class of citrus fruits contains, in addition to the large percentages of terpenes and ldehydes usually obtained, notable amounts of those flavoring-resins largely in excess of and differing in character as a whole from those heretofore obtained and composed of a series of acid resins and neutral resins amounting in the aggregate to six to ten per cent. of tho olco-resin extracted. These resins so supplement and modify the flavoring power of the citrnl of the oil that my product possesses a flavor and aroma more nearly resembling that of the fresh fruit.

It will now proceed to describe my process or method of extraction.

from any of the known pro The peel is removed from the fruit, prefer- 'These cakes are then subjected to pressure,

preferably between iron plates, to extract as much as possible of the water therefrom, for which purpose one may use an ordinary pair of pressure-plates, and of metal some msterial should preferably be'interposed which I will, in addition to holding the pulp between the plates, operate to preserve it from contact with the metal. in practice I use a pair of metal plates having annealed steel surfaces, linen cloths being interposed between the ground peel and the face of the metal plates. After this step the pressed cakes are broken up and ground in. a mill to a time flour in order to burst all the oil-cells and separate both the essential oil and the resinous constituent. Preferably the grinding is effected from coarse to line by employment of difierentiated'roils, the corrugations in each. varying from coarse to line. The resultant flour is gathered into suitable receptacles or conveyors, whereby it is delivered into the extractors in which a volatile sclvent such as carbonjdisuliid, carbon totrachlorid, ethyl ether, or petroleum etheris forced by air-pressine, for which purpose i prefer to use series of ordinary extractors discharging one into the other, with the result that the solvent takes up the oil constituent and the resinous matter. The woduct thus taken up is then run into a still, to which snil'icient heat is applied to vaporize the solvent, leaving the else-resin a 1 68i due. The latter is then subjected to any purification process, such as a heated-air current, to drive oil any remaining traces of the solvent employed.

My process described (.liifers cssentialiy for the extraction ol the cons .ucntolls from the pool of nitrous fruits chiefly in the prcses employed liminary extraction, of the contained water from the ground peel, the graduated pulverization thereof to thoroughly break up the oilcell's, followed by the employment of a volatile solvent to extract from the mass the constituent oil and resins. That these diiferencesare substantial is evidenced by the fact that my process results in a new product, in that it contains, in addition to the essential oil usually obtained, a very much larger percentage of acid resins and an equally large percentage of neutral solid resins, the latter of which have never heretofore been obtained in any appreciable quantity, if at all, by any known 5*process.

izo ral and aldehydes, 1.28 per cent.; terpenes,

' 88.36 per cent, boiling at 175 centigrade un- I der normal pressure; specific gravity, 0.856? at 150 centigrade; optical rotation,'88.46, and of the first ten per cent. of, the distillate 5 90; resins, both acid and neutral, 10.36 per cent.

. Concrete oleo-resin from lemon-peel: citral and aldehydes, 6.83 per cent.-; terpenes, 84.70 per cent, boiling at l72\centigrade under 3 normal pressure; specific gravity, 0.664 at 150 centigrade; optical rotation 52.7 5, and of the first ten per cent. of the distillate 54.25; resins, both acid and neutral, 8.61 per cent. These resins in both instances containa series'of acids to which no one formula, such essential oils of this class, can be applied. llhey consist of one or more solid hydrocarbons or neutral resins and a series of aromatic 4, to bitter (but not astringent) resin .acids in about equal proportions. The solid hydrocarbons or neutral resins that were obtained in my analyses are not distillable with steam, but are all soluble in hot eighty-five-per-cent. alcohol. On being precipitated therefrom they crystallize on cooling and melt at 127 to 130 centigrade (orange oleo-resin) and 120 to 125 centigrade, (lemon oleo-resin.) That these resin acids above referred to form a se- .5 ries was determined bythe results of treatment gives or at least dominates the flavoring power, and no essential oil or oleo-resin from the class of citrus fruits prior to that result mg from my process isv known to contain so as that used to designate the resins of known remarkably high a percentage of acid resinous constituent; and none known to contain the solid hydrocarbons or neutral resins found in mine, the presence of which is further shown as well by the-;higiier specific gravity as by the/lesse'r degree of optical rotation, which is nfuch lower than the normal for the essential oils or oleo-resins derived from the use of processes'by' fexpression and distillation commonly employed. I have hereinabove stated at somelength the several steps in detail constituting my new steps facilitated if the contained water in the peel is removed after grinding and: before pulveri zation, the surface of the pressureplates covered by linen cloths, which operate homes a protection from the metal and as an 7 absorbent of the water, and the employment of a series of extractors discharging one 'nto the other, while the product will be puremif after evaporation of the volatile solvent in a heated still the resultant oleo-resin is subjectedto a heated-air current to drive off any adhering traces of the volatile solvent-employed. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is v 1. The herein-described process of extracting oleo-resin from the peel of citrus fruits, such as lemon and orange, which consists in thoroughly breaking up the oil-cells by successively grinding and pulverizing the same,

' then extracting the essential oil and flavoringresins from the pulverized mass by means of a volatile solvent, and finally purifiying the resultant product by evaporation of the solvent employed.

2. The herein-described process of extracting oleo-resin from the peel of citrus fruits,

such as lemon and orange, which consists in coarsely grinding the peel and forming it into compact cakes, then drawingotf the contained water by subjecting these cakes to pressure between pressure-plates protected by linen cloths, then pulverizing the mass to a fineflour, then submitting the pulverized mass, in suitable extractors, to the action of a volatile solvent of the oil and resin constituents, and withdrawingthe solutioni and'linally separating the solvent from the extracted oleoresin. 7

3. The herein-described process of extractall adhering traces of the solvent by subjecting oleo-resin from the peel of citrus'fruits, ing the isolated oleo-resin to a heated-air cursuch as lemon and orange, which consists in rent. coarsely grinding the peel,- drawing off the, Intestimony whereoflhavehereunto aflixed 5 Water contained (therein by fressurelbetween my signature this 2d day of June, A. D. 1903. 5

surface-protecte pressure-p ates, pu verizing the mass to a flour, submitting the mass-to the EDWARD SHEEHAN action of a volatile solvent of the constituent Witnesses: oil and resins, leading the solution to a suit-' H. T. GULLMANN, able vaporizingvessel, and finally drawing off A. M. BIDDLE. 

